Module Name: src
Committed By: hannken
Date: Wed May 24 09:54:40 UTC 2017
Modified Files:
src/sys/miscfs/genfs: layer_vnops.c
Log Message:
Protect layer_getpages against vnodes disappearing during a
forced unmount.
To generate a diff of this commit:
cvs rdiff -u -r1.64 -r1.65 src/sys/miscfs/genfs/layer_vnops.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/miscfs/genfs/layer_vnops.c
diff -u src/sys/miscfs/genfs/layer_vnops.c:1.64 src/sys/miscfs/genfs/layer_vnops.c:1.65
--- src/sys/miscfs/genfs/layer_vnops.c:1.64 Sun May 7 08:21:57 2017
+++ src/sys/miscfs/genfs/layer_vnops.c Wed May 24 09:54:40 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: layer_vnops.c,v 1.64 2017/05/07 08:21:57 hannken Exp $ */
+/* $NetBSD: layer_vnops.c,v 1.65 2017/05/24 09:54:40 hannken Exp $ */
/*
* Copyright (c) 1999 National Aeronautics & Space Administration
@@ -170,7 +170,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: layer_vnops.c,v 1.64 2017/05/07 08:21:57 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: layer_vnops.c,v 1.65 2017/05/24 09:54:40 hannken Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -183,6 +183,7 @@ __KERNEL_RCSID(0, "$NetBSD: layer_vnops.
#include <sys/buf.h>
#include <sys/kauth.h>
#include <sys/fcntl.h>
+#include <sys/fstrans.h>
#include <miscfs/genfs/layer.h>
#include <miscfs/genfs/layer_extern.h>
@@ -790,6 +791,8 @@ layer_getpages(void *v)
int a_flags;
} */ *ap = v;
struct vnode *vp = ap->a_vp;
+ struct mount *mp = vp->v_mount;
+ int error;
KASSERT(mutex_owned(vp->v_interlock));
@@ -800,7 +803,19 @@ layer_getpages(void *v)
KASSERT(vp->v_interlock == ap->a_vp->v_interlock);
/* Just pass the request on to the underlying layer. */
- return VCALL(ap->a_vp, VOFFSET(vop_getpages), ap);
+ mutex_exit(vp->v_interlock);
+ fstrans_start(mp, FSTRANS_SHARED);
+ mutex_enter(vp->v_interlock);
+ if (mp == vp->v_mount) {
+ /* Will release the interlock. */
+ error = VCALL(ap->a_vp, VOFFSET(vop_getpages), ap);
+ } else {
+ mutex_exit(vp->v_interlock);
+ error = ENOENT;
+ }
+ fstrans_done(mp);
+
+ return error;
}
int
